Normal nose breathing helps us to use our own Nitric Oxide that is generated in the sinuses. The main roles of NO – Nitric Oxide and its effects have been discovered quite recently (in the last 20 years). Three scientists even received a Nobel Prize for their discovery that a common drug, nitroglycerin (used by heart patients for almost a century), is transformed into Nitric Oxide. NO – Nitric Oxide dilates blood vessels of heart patients, reducing their blood pressure and heart rate. Hence, they can survive a heart attack. This substance or gas is produced in various body tissues, including nasal passages. As a gas, it is routinely measured in exhaled air coming from nasal passages.

Nose breathing delivers nitric oxide to lungs, blood and cells.

Functions of Nitric Oxide are:

1. Destruction of viruses, parasitic organisms, and malignant cells in the airways and lungs by inactivating their respiratory chain enzymes.

2. Regulation of binding – release of O2 to hemoglobin. This effect is similar to the CO2 function (the Bohr Effect).

3. Vasodilatation of arteries and arterioles (regulation of blood flow or perfusion of tissues).

6. Neurotransmission. Memory, sleeping, learning, feeling pain, and many other processes are possible only with NO-Nitric Oxide present (for transmission of neuronal signals).

The mouth, according to Doctor Buteyko, is created by nature for eating, drinking, and speaking. At all other times, it should be closed. Obviously, during mouth breathing it is not possible to utilize one’s own Nitric Oxide which is produced in the sinuses.

Our nasal passages are created to humidify, clean and warm the incoming flow of air due to the layers of protective mucus. This thin layer of mucus can trap about 98-99 percent of bacteria, viruses, dust particles, and other airborne objects.

If you are an endurance athlete and an asthmatic, you must train mostly, or even better, only, with nasal breathing. For really important competitions, you can use the mouth for breathing, but only if you have no current problems with your asthma. Sport training is useful due to its aerobic training effect. This is achievable while breathing only through the nose, as one Australian study confirmed (Morton et al, 1995).

A group of US doctors from the Department of Surgery, University of Chicago even wrote an article with the title “Observations on the ability of the nose to warm and humidify inspired air”.

This is another advantage of nasal breathing. The thin layer of mucus moves as a long carpet from sinuses, bronchi and other internal surfaces towards the stomach. Therefore, objects trapped by the mucus are discharged into the stomach, where GI enzymes and hydrochloric acid make bacteria, viruses and fungi either dead or weak. Later, along the digestive conveyor, some of these pathogens (dead or weak) can penetrate from the small intestine into the blood (due to the intestinal permeability effect). Since these pathogens are either dead or weakened, they can not do much harm (cannot cause infections). Moreover, they can provide a lesson for the immune system. This is exactly how natural auto-immunization can work with success.

Medical doctors and nurses inject vaccines with dead or weakened bacteria or viruses so as to teach and strengthen our immune response to these pathogens. Therefore, nasal breathing creates conditions for natural self-immunization.

To summarize – maintaining a keen sense of smell is very important for enjoying life and for safety and social acceptance. Think of all the beautiful smells we enjoy with our nose. Smell influences our behavior, our memories, and many autonomic nervous system functions which are below the level of conscious awareness. The receptors in the nose, known as olfactory bulbs, are direct extensions of a part of the brain known as the hypothalamus. The hypothalamus, also known as the Brain’s brain, is responsible for many functions in our bodies, particularly those that we consider automatic: heartbeat, blood pressure, thirst, appetite, and of course, the cycles of sleeping a waking. The hypothalamus is also responsible for generating chemicals that influence memory and emotion.